feat: clean arch refactor

[9sneha-n]

📌 References

• Issue: Closes https://app.clickup.com/t/8694tp2rg, #8694tp2rg

📝 Implementation

1. Refactor : Rename DiseaseOutbreakEventBaseAttrs to EventTracker to make more meaningful entities. Now, a DiseaseOutbreak event is a aggregate of all other entities - EventTracker, RiskAssessment, IncidentActionPlan etc.
2. Refactor: Rename DiseaseOutbreakRepository to EventTrackerRepository because we were actually getting the Event Tracker info in this repository. We aggregate the data into a DiseaseOutbreakEvent in GetDiseaseOutbreakByIdUseCase.

📹 Screenshots/Screen capture

🔥 Notes to the tester

[9sneha-n]

After discussion with Jorge, we need a bigger refactor using aggregator design. will reopen this PR with more changes at a later time.